/*
 *  linux/kernel/signal.c
 *
 *  (C) 1991  Linus Torvalds
 */


#include "../include/linux/sched.h"
#include "../include/linux/kernel.h"
#include "../include/asm/segment.h"
#include "../include/errno.h"


int sys_sgetmask()
{
    return current->blocked;
}

int sys_ssetmask(int newmask)
{
    int old=current->blocked;

    current->blocked = newmask & ~(1<<(SIGKILL-1)) & ~(1<<(SIGSTOP-1));
    return old;
}

int sys_sigpending(sigset_t *set)
{
    /* fill in "set" with signals pending but blocked. */
    verify_area(set,4);
    put_fs_long(current->blocked & current->signal, (unsigned long *)set);
    return 0;
}

/* atomically swap in the new signal mask, and wait for a signal.
 *
 * we need to play some games with syscall restarting.  We get help
 * from the syscall library interface.  Note that we need to coordinate
 * the calling convention with the libc routine.
 *
 * "set" is just the sigmask as described in 1003.1-1988, 3.3.7.
 * 	It is assumed that sigset_t can be passed as a 32 bit quantity.
 *
 * "restart" holds a restart indication.  If it's non-zero, then we
 * 	install the old mask, and return normally.  If it's zero, we store
 * 	the current mask in old_mask and block until a signal comes in.
 */
int sys_sigsuspend(int restart, unsigned long old_mask, unsigned long set)
{
    extern int sys_pause(void);

    if (restart) {
        /* we're restarting */
        current->blocked = old_mask;
        return -EINTR;
    }
    /* we're not restarting.  do the work */
    *(&restart) = 1;
    *(&old_mask) = current->blocked;
    current->blocked = set;
    (void) sys_pause();			/* return after a signal arrives */
    return -ERESTARTNOINTR;		/* handle the signal, and come back */
}

static inline void save_old(char * from,char * to)
{
    int i;

    verify_area(to, sizeof(struct sigaction));
    for (i=0 ; i< sizeof(struct sigaction) ; i++) {
        put_fs_byte(*from,to);
        from++;
        to++;
    }
}

static inline void get_new(char * from,char * to)
{
    int i;

    for (i=0 ; i< sizeof(struct sigaction) ; i++)
        *(to++) = get_fs_byte(from++);
}

int sys_signal(int signum, long handler, long restorer)
{
    struct sigaction tmp;

    if (signum<1 || signum>32 || signum==SIGKILL || signum==SIGSTOP)
        return -EINVAL;
    tmp.sa_handler = (void (*)(int)) handler;
    tmp.sa_mask = 0;
    tmp.sa_flags = SA_ONESHOT | SA_NOMASK;
    tmp.sa_restorer = (void (*)(void)) restorer;
    handler = (long) current->sigaction[signum-1].sa_handler;
    current->sigaction[signum-1] = tmp;
    return handler;
}

int sys_sigaction(int signum, const struct sigaction * action,
                  struct sigaction * oldaction)
{
    struct sigaction tmp;

    if (signum<1 || signum>32 || signum==SIGKILL || signum==SIGSTOP)
        return -EINVAL;
    tmp = current->sigaction[signum-1];
    get_new((char *) action,
            (char *) (signum-1+current->sigaction));
    if (oldaction)
        save_old((char *) &tmp,(char *) oldaction);
    if (current->sigaction[signum-1].sa_flags & SA_NOMASK)
        current->sigaction[signum-1].sa_mask = 0;
    else
        current->sigaction[signum-1].sa_mask |= (1<<(signum-1));
    return 0;
}

/*
 * Routine writes a core dump image in the current directory.
 * Currently not implemented.
 */
int core_dump(long signr)
{
    return(0);	/* We didn't do a dump */
}

int do_signal(long signr,long eax,long ebx, long ecx, long edx, long orig_eax,
              long fs, long es, long ds,
              long eip, long cs, long eflags,
              unsigned long * esp, long ss)
{
    unsigned long sa_handler;
    long old_eip=eip;
    struct sigaction * sa = current->sigaction + signr - 1;
    int longs;

    unsigned long * tmp_esp;

#ifdef notdef
    printk("pid: %d, signr: %x, eax=%d, oeax = %d, int=%d\n",
		current->pid, signr, eax, orig_eax,
		sa->sa_flags & SA_INTERRUPT);
#endif
    if ((orig_eax != -1) &&
        ((eax == -ERESTARTSYS) || (eax == -ERESTARTNOINTR))) {
        if ((eax == -ERESTARTSYS) && ((sa->sa_flags & SA_INTERRUPT) ||
                                      signr < SIGCONT || signr > SIGTTOU))
            *(&eax) = -EINTR;
        else {
            *(&eax) = orig_eax;
            *(&eip) = old_eip -= 2;
        }
    }
    sa_handler = (unsigned long) sa->sa_handler;
    if (sa_handler==1)
        return(1);   /* Ignore, see if there are more signals... */
    if (!sa_handler) {
        switch (signr) {
            case SIGCONT:
            case SIGCHLD:
                return(1);  /* Ignore, ... */

            case SIGSTOP:
            case SIGTSTP:
            case SIGTTIN:
            case SIGTTOU:
                current->state = TASK_STOPPED;
                current->exit_code = signr;
                if (!(current->p_pptr->sigaction[SIGCHLD-1].sa_flags &
                      SA_NOCLDSTOP))
                    current->p_pptr->signal |= (1<<(SIGCHLD-1));
                return(1);  /* Reschedule another event */

            case SIGQUIT:
            case SIGILL:
            case SIGTRAP:
            case SIGIOT:
            case SIGFPE:
            case SIGSEGV:
                if (core_dump(signr))
                    do_exit(signr|0x80);
                /* fall through */
            default:
                do_exit(signr);
        }
    }
    /*
     * OK, we're invoking a handler
     */
    if (sa->sa_flags & SA_ONESHOT)
        sa->sa_handler = NULL;
    *(&eip) = sa_handler;
    longs = (sa->sa_flags & SA_NOMASK)?7:8;
    *(&esp) -= longs;
    verify_area(esp,longs*4);
    tmp_esp=esp;
    put_fs_long((long) sa->sa_restorer,tmp_esp++);
    put_fs_long(signr,tmp_esp++);
    if (!(sa->sa_flags & SA_NOMASK))
        put_fs_long(current->blocked,tmp_esp++);
    put_fs_long(eax,tmp_esp++);
    put_fs_long(ecx,tmp_esp++);
    put_fs_long(edx,tmp_esp++);
    put_fs_long(eflags,tmp_esp++);
    put_fs_long(old_eip,tmp_esp++);
    current->blocked |= sa->sa_mask;
    return(0);		/* Continue, execute handler */
}
